Tutorial by Examples: l

Processing the buffer via a callback

You can apply any kind of additional processing to the output by passing a callable to ob_start(). <?php function clearAllWhiteSpace($buffer) { return str_replace(array("\n", "\t", ' '), '', $buffer); } ob_start('clearAllWhiteSpace'); ?> <h1>Lorem Ipsum&l...

PHP • Output Buffering

Variables

Variables you have provided in your view context can be accessed using double-brace notation: In your views.py: class UserView(TemplateView): """ Supply the request user object to the template """ template_name = "user.html" def get_context_data...

Django • Templating

Uploading a file using the Dropbox Python SDK

This uses the Dropbox Python SDK to upload a file to the Dropbox API from the local file as specified by file_path to the remote path as specified by dest_path. It also chooses whether or not to use an upload session based on the size of the file: f = open(file_path) file_size = os.path.getsize(fi...

Dropbox API • Uploading a file

Increasing Animation Performance Using the `will-change` Attribute

When creating animations and other GPU-heavy actions, it's important to understand the will-change attribute. Both CSS keyframes and the transition property use GPU acceleration. Performance is increased by offloading calculations to the device's GPU. This is done by creating paint layers (parts of...

CSS • Animations

Simple Pivot - Static Columns

Using Item Sales Table from Example Database, let us calculate and show the total Quantity we sold of each Product. This can be easily done with a group by, but lets assume we to 'rotate' our result table in a way that for each Product Id we have a column. SELECT [100], [145] FROM (SELECT ItemI...

Microsoft SQL Server • PIVOT / UNPIVOT

Prototypal inheritance

Suppose we have a plain object called prototype: var prototype = { foo: 'foo', bar: function () { return this.foo; } }; Now we want another object called obj that inherits from prototype, which is the same as saying that prototype is the prototype of obj var obj = Object.create(prototype); N...

JavaScript • Inheritance

Handling the error when getting metadata for a non-existing path using the Dropbox .NET library

This example uses the Dropbox .NET library to try to get the metadata for an item at a particular path, and checks for a NotFound error: try { var metadata = await this.client.Files.GetMetadataAsync("/non-existant path"); Console.WriteLine(metadata.Name); } catch (Dropbox.Api.A...

Dropbox API • Getting file metadata

For loop

A for loop executes statements in the loop body, while the loop condition is true. Before the loop initialization statement is executed exactly once. After each cycle, the iteration execution part is executed. A for loop is defined as follows: for (/*initialization statement*/; /*condition*/; /*it...

C++ • Loops

Getting the active theme URL

<?php echo esc_url( get_bloginfo( 'stylesheet_directory' ) ); ?> Output http://example.com/wp-content/themes/twentysixteen Alternatives Internally, get_bloginfo( 'stylesheet_directory' ) calls get_stylesheet_directory_uri(), so you may want to use that instead: <?php echo esc_url( ...

WordPress • get_bloginfo()

Hello World

This program, saved to a file named HelloWorld.dpr, compiles to a console application that prints "Hello World" to the console: program HelloWorld; {$APPTYPE CONSOLE} begin WriteLn('Hello World'); end.

Embarcadero Delphi • Getting started with Embarcadero Delphi

Generalized capture

C++14 Lambdas can capture expressions, rather than just variables. This permits lambdas to store move-only types: auto p = std::make_unique<T>(...); auto lamb = [p = std::move(p)]() //Overrides capture-by-value of `p`. { p->SomeFunc(); }; This moves the outer p variable into th...

C++ • Lambdas

Default capture

By default, local variables that are not explicitly specified in the capture list, cannot be accessed from within the lambda body. However, it is possible to implicitly capture variables named by the lambda body: int a = 1; int b = 2; // Default capture by value [=]() { return a + b; }; // OK;...

C++ • Lambdas

Your First Controller

A controller is a basic structure used in Angular to preserve scope and handle certain actions within a page. Each controller is coupled with an HTML view. Below is a basic boilerplate for an Angular app: <!DOCTYPE html> <html lang="en" ng-app='MyFirstApp'> <head...

AngularJS • Controllers

Console.ReadLine()

Dim input as String = Console.ReadLine() Console.ReadLine() will read the console input from the user, up until the next newline is detected (usually upon pressing the Enter or Return key). Code execution is paused in the current thread until a newline is provided. Afterwards, the next line of co...

Visual Basic .NET Language • Console

Console.WriteLine()

Dim x As Int32 = 128 Console.WriteLine(x) ' Variable ' Console.WriteLine(3) ' Integer ' Console.WriteLine(3.14159) ' Floating-point number ' Console.WriteLine("Hello, world") ' String ' Console.WriteLine(myObject) ' Outputs the value from calling myObject.ToString() The Console.Wri...

Visual Basic .NET Language • Console

Console.Write()

Dim x As Int32 = 128 Console.Write(x) ' Variable ' Console.Write(3) ' Integer ' Console.Write(3.14159) ' Floating-point number ' Console.Write("Hello, world") ' String ' The Console.Write() method is identical to the Console.WriteLine() method except that it prints the given argumen...

Visual Basic .NET Language • Console

Avoiding namespace collisions

Libraries other than jQuery may also use $ as an alias. This can cause interference between those libraries and jQuery. To release $ for use with other libraries: jQuery.noConflict(); After calling this function, $ is no longer an alias for jQuery. However, you can still use the variable jQuery...

jQuery • Getting started with jQuery

Creating a backup of a database or table

Create a snapshot of a whole database: mysqldump [options] db_name > filename.sql Create a snapshot of multiple databases: mysqldump [options] --databases db_name1 db_name2 ... > filename.sql mysqldump [options] --all-databases > filename.sql Create a snapshot of one or more tables...

MySQL • Backup using mysqldump

Restoring a backup of a database or table

mysql [options] db_name < filename.sql Note that: db_name needs to be an existing database; your authenticated user has sufficient privileges to execute all the commands inside your filename.sql; The file extension .sql is fully a matter of style. Any extension would work. You cannot spe...

MySQL • Backup using mysqldump

Generic lambdas

c++14 Lambda functions can take arguments of arbitrary types. This allows a lambda to be more generic: auto twice = [](auto x){ return x+x; }; int i = twice(2); // i == 4 std::string s = twice("hello"); // s == "hellohello" This is implemented in C++ by making the closur...

C++ • Lambdas